Combined printing and developing machine



April 1945- H. G. MACDONALD ET AL 2,373,040

COMBINED PRINTING AND DEVELOPING MACHINE Filed March 28, 1942 2 SheetsSheet l April 3, 1945. H, G. MACDONALD ET AL 3,

COMBINED PRINTING AND DEVELOPING MACHINE Filed March 28, 1942 2 Sheets-Sheet 2 Patented Apr. 3', 1945 COMBINED PRINTING AND DEVELOPING MACHINE t Herbert G. Macdonald, Mount Prospect, and

Joseph Hruby.

poration of Illinois Chicago, Charles Bruning 00., Inc.,

111., assignors to Chicago, Ill., a cora 1 Application March 28, 1942, Serial No. 438,702

3 Claim.

,This invention is directed to a machine which by continuous operation performs all the steps in the photo-printing, developing and drying of developed diazo-type prints taken from tracings or likelmpressions which for convenience are to be included under the term tracings."

The machine is so designed that the Only work required of the operator is to introduce the tracings and print sheets in registering relation into the machine at the feeding, point, after which the tracings and print. sheets will be momentarily subjected to the required degree of illumination to re8 S r the impression on the sensitized surface of the sheets, after which the tracings will be promptly 'dischargedfrom the machine so that they maybe, immediately employed in succeeding operations while the prints proceed onwardly to receive a coating ofthe liquid developer on the sensitized side, after which: they are carried through a-drying chamber and arounda heated roller which contacts the rear'unmoistened faces of the sheets and feversely bends them, and in drying sets the fibers of the sheetsin such a way as to prevent upward curling of thelsheets after they-are delivered from the machine. I

In certain machines of this general type, it. has

been customary to tized surface of moistening of the sensitized surface, but this method of treating the sheets is in some respects unsatisfactory; since the moistening of the sheet on each side wets the paper throughout, causing it to become sticky and soggy, thereby requiring the use of strippers or the liketo prevent ad-. hesion to thefeeding rolls and also reducing its tensile strength, thereby rendering the smooth moistenthe rear or non-sensiand even feeding of the sheets more difficult, At

the same time, the excessive vmoistening of'the sheets renders thefdrying operation more dimcult and is wasteful in the expenditure of heat while the" employment of 'reverse'moistening rolls or thelike complicates the structure and increases the overalldimensions of the machine and is otherwise objectionable. h j

By the use of what may be conveniently termed a heated bending or setting roll, theindi-' vidual sheets are delivered a smooth dry condition, and substantially flat, although they may normally have a slight rearsince they will lie substantially flat when'stacked, and will not tend to curve upwardly and thus interfere with the easy and convenient reading or inspection of the sheets.

the sheet to compensate for thefrom the machine in i Further objects and details will appear from V 22, so disposed that the active turns of "surround about four-fifths of the cylinder at the mounted within a cabinet which includes end housings l0 and H for enclosing the light and speed controls and the driving train which need not be described in detail. The superposed and registered tracings T and print sheets P are laid upon a forwardly projecting shelf l2 and fed inwardly in unison beneath throated guide plates l3 and I4, the latter of which deflects the tracing-print assembly downwardly against the surface of a pyrex cylinder I5, which is transparent to the ultra-violet rays from a centrally disposed mercury vapor quartz lamp ii of high intensity, which provides high speed printing and uniform light distribution without flickering. Contact with thecylinder is maintained by endless tapes I! which pass around guide rolls l8, I8, 20, 2|, the tapes rear, leaving the front of the cylinder open save for the presence of a light shield 23 so disposed as to protect the eyes of the operator. The return of the tapes is behind the cylinder.

For purposes of clarity, the length and thickness of the tracings and the sheets are exaggerated, but it will be understood that the length is not limited, and the width is limited only by the width of the machine, so that the smallest sheets as well as continuous strips may be accommodated. After the tracing-print assembly has been fed around the light cylinder and returned to the front of the machine, with the tracing in contact with the cylinder, the printing is complete and the tracing is immediately returned for re-use. The separation is effected at this point by a vacuum separator roll 24 provided in its wall with a multiplicity of slots or apertures 25 of any suitable shape or arrangement, which afford a suction against the surface of the tracing, without, however, diverting the printed sheet from its upward path which is initiated by the contact of a stripper bar 26 and an oblique guide blade 21 which turn the sheet upwardly between the vacuum stripper roll 24 and the tape guide roll 22. In these circumstances, the sheet pan 28 within convenient from the tapes I! by the action of a stripper 29, and passes upwardly behind a'guide, plate 30 and between feed rolls 3| 'and'32, the latter of which may be faced with rubber strips 33 to afford the necessary friction. The sheet is diverted forwardly by a series of crescent shaped guide fingers 34 and over theltop of an applicator roll 35 which dips down into a trough 36 towhich a constant supply of developer is fed. The sheet is held against the applicator roll by feed and contact rolls 3'! and 38 carried by frame members 39, and the sheets are diverted upwardly by a bank of guide fingers 40 strung upona rod 4| and held in position by the provision of notches 42 which straddlea fixed bar 4 3 cooperating with a stop rod 44 which holds the curved acting edges of the guide fingers in close proximity to the roll 38, and at the same time permits the entire bank of guide fingers to be readily removed in order to secure access to the interior of the machine.

The leading end of the upwardly traveling'sheet is next engaged by the adjacent turns-of outer and inner tapes 45 and 46. The outer tapes pass around upper and lower feed rolls '41 and48 and behind a tensioning roll 49. The inner tapes 46 pass over a forward feed roll 50 and around a rear feed roll over a tensioning roll 52 and under a lower forward roll 53. The inner tapes'46 coact with upper tapes 54 carried by forward and rear feed rolls 55 and 56 and carried under a tensioning roll 51. In order to guide the sheets as they enter between the tapes 46and 54, a bank of arcuate guide fingers 54 is provided which strip the sheets from the tapes 45 and divert them rearwardly toward the tapes 54. The tapes 4B and 54 run'in a substantially horizontal direction and within an enclosed drying chamber 58 which extends rearwardly from the cabinet of the machine and which comprises side walls 59, a forward hood 60, and a top or roof 6 l. The heating chamber is open at its rear under portion 62 for the discharge of the sheets into an adjustable pan or tray 63.

The sheets transported rearwardly between the tapes 46 and 54 are carried around a power driven heated bending and setting roll 64 located near the rear end of the drying chamber 58, and the sheets are compressed firmly against the surface of the roll 64 by tapes 65 which pass around rolls 66, 61, 68, the rolls 66 and 68'being disposed directly above and below the axis of the roll 64, so

"that'the forward turns of the tapes willi'press firmly against the rear half of the roll 64' and hold the sheets firmly against the roll, with their moistened sensitized faces presented outwardly, so that as the sheets pass around the heated roll they will be dried from the reverse side outwardly, and the fibers will be given a permanent set,

which counteracts any tendency of the sheets to curl upwardly when released.

The drying and setting roll may be heated in any suitable manner, as for instance by strip electric heating elements 69 or the like, and the drying chamber may also be heated by suitable means, as for instance strip heating elements of suflicient capacity toremove most of the moisture during the passage of the sheets through the drying chamber, but leaving them in a slightly damp condition as they encounter the heated surface of the bending and setting roll which applies the final heat required in giving the desired permanent set to the sheets prior to their final delivery from the machine and into the tray 63.

It will be understood that the various feeding and tape carrying rolls are driven by suitable roll in a slightly-damp condition; means for pressing the sheet around the setting roll with 't'er'ially improved.

gearing at a uniform feeding speed,=s'o thatthe "sheets will, befsmoothly and evenly "carried condition, and'there will be no danger of sticking or adhering to the rolls which contact the rear surface.

, By eliminating the rnoistene'rs for the rear faces of the sheets, the height of the machine is materially reduced, and "likewise. the length of travel through thedrying 'chamber may also be reduced, so that the overall dimensions and general arrangement 'of the machine will be rna- Although the invention, has

v been describedin considerable detail, it will be understood that the arrangement of the various mechanisms shown a serves merely for purposes of illustratiom and that numerous changes in the arrangement a'nd locationof the various mechanisms may be made without departing from the spirit of theinvention.

We claim: I a 1. A developing machine er "the type adapted to pass out sheets of diazoprihting paper and the liketherethrough, including-applicator means for applying a liquid developer to the sensitized face only of the printing paper, a drying chamber, a setting roll, conveying means'adapted to carry a sheet from the applicator means to thesetting roll while maintaining it free from the applica-- tion of moisture 'tojthe back thereof; the relation" of the speed and length of the conveying means and the characteristics'of the drying chamber being such asto deliver the sheets to thesetti'ng its sensitized faceout, means to heat the setting roll to produce a flattening set in the sheet, said apparatus being, adapted to discharge the sheetwithout so affecting-said flattening set as to cause the sheet tocurl'with its sensitized faceinward. Y

2. A developingdnachine cf the type adapted= to pass cut sheets of printing paper and the like therethrough, including applicator means for applying a liquid developer to the sensitzed face only of the printiuglpapeiya drying chamber, a

settin roll, conveying means adapted to carry a sheet from the applicator means to the setting rcll while maintaining it free from the application of moisture to the back thereof; the relation of the speed-and length of the conveying means and'the characteristics of the drying chamber being such as to deliver the sheets to the setting roll in a slightly damp condition, means for pressing the sheet around the setting roll with its sensitized face out, means to heat the settin ly damp condition, means for pressing the sheet 10 around the setting roll with its sensitized face out, means to heat the setting roll to substantially dry the sheet in contact therewith and produce a flattening set in the sheet, said apparatus being adapted to discharge the sheet without so affecting said flattening set as to cause the sheet to curl with its sensitized face inward.

HERBERT G. MACDONALD. JOSEPH HRU'BY. 

